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More Los Angeles Fire Images
Triple-digit temperatures, e
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9/1/09
| Description |
Triple-digit temperatures, extremely low relative humidities, dense vegetation that has not burned in decades, and years of extended drought are all contributing to the explosive growth of wildfires throughout Southern California. The Station fire, which began Aug. 26, 2009, in La Canada/Flintridge, not far from NASA's Jet Propulsion Laboratory, had reportedly burned 105,000 acres (164 square miles) of the Angeles National Forest by mid-day Aug. 31, destroying at least 21 homes and threatening more than 12,000 others. It is one of four major fires burning in Southern California at the present time. This image was acquired mid-morning on Aug. 30 by the backward (northward)-viewing camera of the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra satellite. The image is shown in an approximate perspective view at an angle of 46 degrees off of vertical. The area covered by the image is 245 kilometers (152 miles) wide. Several pyrocumulus clouds, created by the Station Fire, are visible above the smoke plumes rising from the San Gabriel Mountains north of Los Angeles in the left-center of the image. Smoke from the Station fire is seen covering the interior valleys along the south side of the San Gabriel Mountains, along with parts of the City of Los Angeles and Orange County, and can be seen drifting for hundreds of kilometers to the east over the Mojave Desert. The accompanying plots are histograms that display the heights of the smoke plumes and wind speeds. In this data set, the plume is injecting smoke more than 7 kilometers (4.3 miles) above sea level. MISR observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. This image was generated from a portion of the imagery acquired during Terra orbit 51601. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, Md. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center. JPL is a division of the California Institute of Technology. Image Credit: NASA/GSFC/LaRC/JPL, MISR Team |
| Date |
9/1/09 |
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Amazing Andromeda Galaxy
| Title |
Amazing Andromeda Galaxy |
| Description |
The many "personalities" of our great galactic neighbor, the Andromeda galaxy, are exposed in this new composite image from NASA's Galaxy Evolution Explorer and the Spitzer Space Telescope. The wide, ultraviolet eyes of Galaxy Evolution Explorer reveal Andromeda's "fiery" nature -- hotter regions brimming with young and old stars. In contrast, Spitzer's super-sensitive infrared eyes show Andromeda's relatively "cool" side, which includes embryonic stars hidden in their dusty cocoons. Galaxy Evolution Explorer detected young, hot, high-mass stars, which are represented in blue, while populations of relatively older stars are shown as green dots. The bright yellow spot at the galaxy's center depicts a particularly dense population of old stars. Swaths of red in the galaxy's disk indicate areas where Spitzer found cool, dusty regions where stars are forming. These stars are still shrouded by the cosmic clouds of dust and gas that collapsed to form them. Together, Galaxy Evolution Explorer and Spitzer complete the picture of Andromeda's swirling spiral arms. Hints of pinkish purple depict regions where the galaxy's populations of hot, high-mass stars and cooler, dust-enshrouded stars co-exist. Located 2.5 million light-years away, the Andromeda is our largest nearby galactic neighbor. The galaxy's entire disk spans about 260,000 light-years, which means that a light beam would take 260,000 years to travel from one end of the galaxy to the other. By comparison, our Milky Way galaxy's disk is about 100,000 light-years across. This image is a false color composite comprised of data from Galaxy Evolution Explorer's far-ultraviolet detector (blue), near-ultraviolet detector (green), and Spitzer's multiband imaging photometer at 24 microns (red). |
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Iapetus Thermal Radiation Im
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| Description |
Iapetus Thermal Radiation Image |
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This image of the infrared heat radiation from Saturn's moon Iapetus was obtained by the Cassini composite infrared spectrometer instrument 16 hours before Cassini's closest approach to this mysterious moon, on December 31, 2004. The thermal radiation is shown as both a grayscale image, equivalent to what we would see if our eyes were sensitive to infrared wavelengths near 15 microns, and as a color-coded temperature map. A previously-released mosaic obtained by Cassini's imaging camera shortly before the composite infrared spectrometer observation, with similar scale and orientation, is also shown for comparison. Temperatures reach nearly 130 Kelvin (-226 Fahrenheit) at noon on the equator on the dark material that covers most of this side of Iapetus, making high noon on Iapetus's dark side probably the warmest places in the Saturn system. This is much warmer than temperatures on another Saturnian moon, Phoebe, measured by composite infrared spectrometer in June 2004. Those Phoebe temperature measurements peaked near 112 Kelvin (-258 Fahrenheit), because though Phoebe is almost as dark as Iapetus's dark material and absorbs nearly as much sunlight, Phoebe rotates much more quickly (once every 9 hours, compared to 79 days for Iapetus). That means the surface has less time to heat up during the day. Temperatures on Iapetus's bright material are much colder, peaking near 100 Kelvin (-280 Fahrenheit), both because the bright material absorbs less sunlight and because it is further from the equator on this side of Iapetus. Temperatures in the large crater near the center of the disc are slightly different from those in surrounding areas, because sloping surfaces within the crater are warmer where they are tilted towards the Sun and cooler when tilted away from the Sun. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
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Iapetus Surface Composition
| Description |
Iapetus Surface Composition |
| Full Description |
The Cassini visual and infrared mapping spectrometer analyzed the surface composition of Saturn's moon Iapetus as Cassini flew over the polar region on Dec. 31, 2004. The image at left shows the reflectance at 4-microns, which is dominated by the minerals on Iapetus' surface. Two large craters are seen in this image. The polar water ice is relatively dark at this wavelength, so the ice cap is not seen. The next frame shows carbon dioxide on the surface. The carbon dioxide peaks at mid latitudes and shows less strength at the pole and along the equator (the dark band curving near the left edge of the image). The third frame shows the strength of water absorption on Iapetus. The brightest regions are due to water ice near the pole. The grayer areas indicate water bound to minerals on the surface. The color composite shows water as blue, carbon dioxide as green, and non-ice minerals as red. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The visible and infrared mapping spectrometer team is based at the University of Arizona, Tucson. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov. For more information about the visual and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
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The Hole at the Pole
| Description |
The Hole at the Pole |
| Full Description |
The Cassini data presented in this view appear to confirm a region of warm atmospheric descent into the eye of a hurricane-like storm locked to Saturn's south pole. The view shows temperature data from the Cassini spacecraft composite infrared spectrometer overlaid onto an image from the imaging science subsystem wide-angle camera. The composite infrared spectrometer data refer to a depth in Saturn's upper stratosphere where the pressure is 0.5 millibars (324 kilometers above the 1-bar level), a region higher than that imaged by the imaging camera and visual and infrared spectrometer during the same observation period. The composite infrared spectrometer data show a very small hot spot over the pole, similar in size to the "eye" of the storm seen in the imaging science subsystem images. See also Looking Saturn in the Eye and Saturn's Surprisingly Stormy South for related images. The color scale at the bottom indicates the temperature in Kelvin corresponding to the colors of the temperature map. Numbers on the grid correspond to lines of latitude and longitude on the planet. Infrared images taken through the Keck I telescope by ground-based observers had previously shown the south polar spot to be warm. Cassini's composite infrared spectrometer has confirmed this with higher resolution temperature maps of the area (like the map displayed here) and sees a temperature increase of about 2 Kelvin (4 degrees Fahrenheit) at the pole. The temperatures are in the stratosphere and higher up than the clouds seen by the Cassini imaging and visual and infrared mapping spectrometer instruments, but they suggest that the atmosphere sinks over the south pole. Because the pressure increases with depth, the descending atmosphere compresses and heats up. The warmer temperatures over the south pole also indicate that the vortex winds are decaying with height in the stratosphere. The descent implied by the temperatures nicely supports the lower cloud altitudes observed by the imaging camera and visual and infrared spectrometer instruments at the pole. The image and atmospheric data were acquired on Oct. 11, 2006, when Cassini was approximately 340,000 kilometers (210,000 miles) from Saturn. The wide-angle camera image was taken using a spectral filter sensitive to wavelengths of infrared light centered at 752 nanometers. The image has been contrast enhanced using digital image processing techniques. The unprocessed image shows an oblique view toward the pole, and was reprojected to show the planet from a perspective directly over the south pole. Scale in the original image was about 17 kilometers (11 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras, were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org . The composite infrared spectrometer team homepage is at http://cirs.gsfc.nasa.gov/ . *Credit:* NASA/JPL/Space Science Institute/GSFC |
| Date |
November 9, 2006 |
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Iapetus Temperature Variatio
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| Description |
Iapetus Temperature Variation Map |
| Full Description |
This plot shows how daytime temperatures at low latitudes on the dark material on Saturn's moon Iapetus vary with time of day, from about 130 Kelvin (-226 Fahrenheit) at noon to about 70 Kelvin (-334 Fahrenheit) at sunset. The observations are compared to a "forecast" model (green line) which predicts temperatures based on an assumed value of a parameter called the "thermal inertia. This measures how well the surface can retain heat as conditions change. Rock or solid ice has a high thermal inertia, roughly 2,000,000 as measured in the obscure units used for thermal inertia, meaning that it is good at storing heat and cools down or heats up relatively slowly. On Iapetus, in contrast, temperatures drop precipitously in the afternoon as the Sun sinks towards the horizon, and a very small value of the thermal inertia (30,000 units) is needed in the model to match the data. This means that Iapetus's surface is extremely bad at storing heat, and is thus extremely fluffy, probably due to the pulverizing effect of billions of years of meteorite impacts, though the mysterious process that has darkened this side of Iapetus may also have played a role. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
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Enceladus Keeps the Home Fir
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| Description |
Enceladus Keeps the Home Fires Burning |
| Full Description |
On Nov. 9, 2006, Cassini's composite infrared spectrometer captured its first view of the infrared heat radiation emanating from the "tiger stripe" fractures at the south pole of Saturn's moon Enceladus (right) since the discovery of the hot spot 16 months earlier (left). The original discovery was made just before a close flyby of Enceladus on July 14, 2005, and coincided with the discovery of plumes of water-rich gas and ice particles jetting out of the tiger stripes. However, the spacecraft's orbit did not provide any good views of the south pole for follow-up observations until November 2006. The new observations were made from a range of 110,000 kilometers (68,350 miles), slightly more distant than the 80,000-kilometer range (49,700 miles) of the original observations. Comparison of the two images shows that the south polar region continues to be active, and the distribution of temperatures there has changed little in 16 months. The distribution of heat radiation suggests that most or all of the south polar heat comes from the tiger stripes themselves, though the individual stripes are not resolved at the approximate 30-kilometer (19-mile) spatial resolution of these images. The images show the intensity of heat radiation in the 10- to 16-micron wavelength range, translated into temperature and displayed in false color. Peak south polar temperature on both dates reached about 85 Kelvin (minus 306 degrees Fahrenheit), averaged over the 30-kilometer (19-mile) spatial resolution of the data. However, the variation in brightness with wavelength, which is also measured by the composite infrared spectrometer, reveals that the warm region includes small areas, possibly zones a few 100 meters (320 feet) wide along the length of the tiger stripes, that are at higher temperatures, reaching at least 130 Kelvin (minus 225 degrees Fahrenheit) and perhaps much warmer still. While the south polar tiger stripes are almost certainly heated by energy from the moon's interior, daytime regions at low latitudes are warmed by sunlight to temperatures in the high 70s Kelvin (about minus 320 degrees Fahrenheit). The white numbers on the images show west longitudes on Enceladus, which is 500 kilometers (310 miles) in diameter. The dashed line shows the terminator, the boundary between day and night. The blotchy appearance of the cooler regions away from the south pole, and of the sky beyond the globe of Enceladus, is an artifact resulting from the fact that apart from the polar hot spot, the composite infrared spectrometer can barely detect the very faint heat radiation from this very cold moon. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The, composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. *Image Credit:* NASA/JPL/GSFC/Southwest Research Institute |
| Date |
December 22, 2006 |
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Titan Sea and Lake Superior
| Description |
Titan Sea and Lake Superior |
| Full Description |
This side-by-side image shows a Cassini radar image (on the left) of what is the largest body of liquid ever found on Titan's north pole, compared to Lake Superior (on the right). This close-up is part of a larger image (see Titan (T25) Viewed by Cassini's Radar - Feb. 22, 2007) and offers strong evidence for seas on Titan. These seas are most likely liquid methane and ethane. This feature on Titan is at least 100,000 square kilometers (39,000 square miles), which is greater in extent than Lake Superior (82,000 square kilometers or 32,000 square miles), which is one of Earth's largest lakes. The feature covers a greater fraction of Titan than the largest terrestrial inland sea, the Black Sea. The Black Sea covers 0.085 percent of the surface of the Earth, this newly observed body on Titan covers at least 0.12 percent of the surface of Titan. Because of its size, scientists are calling it a sea. The image on the right is from the SeaWiFS project, NASA's Goddard Space Flight Center, Greenbelt, Md. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm. *Credit:* NASA/JPL/GSFC |
| Date |
March 13, 2007 |
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Warm and Dry on Iapetus
| Description |
T |
| Full Description |
The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The Cassini imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/GSFC/SwRI/SSI, This image compares midday temperatures on Saturn's moon Iapetus, recorded by the composite infrared spectrometer instrument during Cassini's close Sept. 10, 2007 flyby, with images of the same region recorded during the same flyby by the Cassini imaging science subsystem, shown on the right. See The Other Side of Iapetus for full imaging mosaic. Smallest features visible in the composite infrared spectrometer image (on the left) are about 8 kilometers (5 miles) across. The red rectangle on the visible light (right) image shows the region covered by infrared spectrometer, which extends a distance of 385 kilometers (240 miles) from 36 north, 212 west to 22 south, 220 west. The composite infrared spectrometer determined surface temperatures by measuring the spectrum of infrared radiation emitted by Iapetus in the 9 to 16 micron wavelength range. The dark regions are warmer because they absorb more of the sunlight shining on Iapetus, so dark spots in the visible (right) image show up as warm spots in the infrared image on the left. Temperatures near the equator vary between about 128 Kelvin (minus 229 degrees Fahrenheit) in the darkest regions and about 113 Kelvin (minus 256 degrees Fahrenheit) in the brightest regions. This relatively small temperature difference has a large effect on Iapetus, because at the temperature of the dark regions, a large amount of water ice, which is abundant on most moon surfaces in the Saturn system, can be lost by evaporation over the several-billion year age of Iapetus' surface. Composite infrared spectrometer scientists calculate that when daytime temperatures reach 128 Kelvin (minus 229 degrees Fahrenheit), about 20 meters (65 feet) of ice can be lost per billion years. In the bright regions, with peak temperatures of 113 Kelvin (minus 256 degrees Fahrenheit), only about 10 centimeters, or 2.5 inches, of ice is lost in the same period. It is thus likely that the ice has evaporated completely from the surface of the dark regions of Iapetus, darkening them further, and has collected in the neighboring bright regions, making them brighter, thereby exaggerating initially modest brightness variations. This process is known as thermal segregation. Models by the composite infrared spectrometer team also show that ice evaporated from the warm dark terrain at low latitudes can collect at higher latitudes, and can thus explain the bright polar caps on the dark leading side of Iapetus as well as the relatively dark equatorial regions on the bright trailing side. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. |
| Date |
October 8, 2007 |
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High Above Saturn's Cloud To
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
These graphs illustrate wind strength (bottom) and temperature above Saturn. The data were acquired by the Cassini spacecraft's composite infrared spectrometer when Saturn had just begun summer in its southern hemisphere. Altitude increases in the upward direction, and Saturn's south pole is to the right. The color red indicates higher temperatures, and stronger winds. As the top graph show, temperatures are cooler in the troposphere (the layer just above the cloud deck). In the upper stratosphere (the layer above the troposphere), temperatures increase toward the south pole. Temperature variation is muted in the upper troposphere. These observed temperature changes allow the east-west winds to be determined. The measured cloud-top winds from NASA's Voyager mission have also been used to create this wind plot. This is the first time that the stratospheric winds have been determined. They show a marked decline of about 140 meters per second (approximately 300 miles per hour) at low latitudes, moving from the cloud tops to higher levels. The origin of this decay, or wind speed reduction, is not known. Temperature maps obtained in the future from Cassini's new position in orbit around Saturn will have higher latitude resolution, and are expected to show more detail, helping us to unravel the riddles of Saturn's winds above the cloud tops. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is located at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://cirs.gsfc.nasa.gov/ . Image Credit: NASA/JPL/GSFC |
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Saturn's Rings, Cold and Col
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
The varying temperatures of Saturn's rings are depicted here in this false-color image from the Cassini spacecraft. This image represents the most detailed look to date at the temperature of Saturn's rings. The image was made from data taken by Cassini's composite infrared spectrometer instrument. Red represents temperatures of about 110 Kelvin (-261 degrees Fahrenheit), and blue 70 Kelvin (-333 degrees Fahrenheit). Green is equivalent to 90 Kelvin (-298 degrees Fahrenheit). Water freezes at 273 Kelvin (32 degrees Fahrenheit). The spatial resolution of the ring portion of the image is 200 kilometers (124 miles). The data show that the opaque region of the rings, like the outer A ring (on the far right) and the middle B ring, are cooler, while more transparent sections, like the Cassini Division (in red just inside the A ring) or the inner C ring (shown in yellow and red), are relatively warmer. The temperature data were taken on July 1, 2004, of the unlit side of the rings. In order to show the full breadth of the rings, a strip of temperature data was mapped onto a picture of the lit side of the rings taken with the Cassini narrow angle camera on May 11, 2004, a little over a month before Saturn orbit insertion. Cassini is too close to the planet and hence no pictures of the unlit side of the rings are available, so the temperature data were mapped onto a picture of the lit side of rings. Saturn is overexposed and pure white in this picture. Saturn's moon Enceladus is visible below the rings, toward the center. The original picture and caption are available at http://photojournal.jpl.nasa.gov/catalog/PIA05410. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science and Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Composite Infrared Spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov . Image Credit: NASA/JPL/GSFC/Ames |
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Auroral "Footprints" of Jupiter's Moons February 27, 2002 A drawing illustrates how flows of electrons steered by Jupiter's magnetic field connect three of Jupiter's large moons with the upper atmosphere near Jupiter's north and south poles. The currents stimulate ultraviolet aurora glows in Jupiter's upper atmosphere. Observations with NASA's Hubble Space Telescope, coordinated with the late 2000 flyby of Jupiter by NASA's Cassini spacecraft, captured those auroral footprints for the moons Io (left), Europa (right) and Ganymede (center). In the illustration, Jupiter's magnetic field lines are presented in blue, the moons' orbital paths around Jupiter in yellow. Pink loops from each of the moons to Jupiter's poles depict the flux tubes that are the paths of powerful electric currents. The Space Telescope Science Institute, Baltimore, Md., manages space operations for Hubble for NASA's Office of Space Science, Washington, D.C. The institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science. Credit: NASA/John Spencer, Lowell Observatory and John Clarke, Boston University More information about the Cassini and Galileo joint observations of the Jupiter system is available online at: http://www.jpl.nasa.gov/jupiterflyby. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo and Cassini missions for NASA's Office of Space Science, Washington, D.C. |
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Saturn's Rings, Cold and Col
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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
The varying temperatures of Saturn's rings are depicted here in this false-color image from the Cassini spacecraft. This image represents the most detailed look to date at the temperature of Saturn's rings. The image was made from data taken by Cassini's composite infrared spectrometer instrument. Red represents temperatures of about 110 Kelvin (-261 degrees Fahrenheit), and blue 70 Kelvin (-333 degrees Fahrenheit). Green is equivalent to 90 Kelvin (-298 degrees Fahrenheit). Water freezes at 273 Kelvin (32 degrees Fahrenheit). The spatial resolution of the ring portion of the image is 200 kilometers (124 miles). The data show that the opaque region of the rings, like the outer A ring (on the far right) and the middle B ring, are cooler, while more transparent sections, like the Cassini Division (in red just inside the A ring) or the inner C ring (shown in yellow and red), are relatively warmer. The temperature data were taken on July 1, 2004, of the unlit side of the rings. In order to show the full breadth of the rings, a strip of temperature data was mapped onto a picture of the lit side of the rings taken with the Cassini narrow angle camera on May 11, 2004, a little over a month before Saturn orbit insertion. Cassini is too close to the planet and hence no pictures of the unlit side of the rings are available, so the temperature data were mapped onto a picture of the lit side of rings. Saturn is overexposed and pure white in this picture. Saturn's moon Enceladus is visible below the rings, toward the center. The original picture and caption are available at http://photojournal.jpl.nasa.gov/catalog/PIA05410. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science and Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Composite Infrared Spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov . Image Credit: NASA/JPL/GSFC/Ames |
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Warm Fractures on Enceladus
| Description |
Warm Fractures on Enceladus |
| Full Description |
This image shows the warmest places in the south polar region of Saturn's moon Enceladus. The unexpected temperatures were discovered by Cassini's composite infrared spectrometer during a close flyby on July 14, 2005. The image shows how these temperatures correspond to the prominent, bluish fractures dubbed "tiger stripes," first imaged by Cassini's imaging science subsystem cameras. Working together the two teams were able to pinpoint the exact location of the warmest regions on Enceladus. The composite infrared spectrometer instrument measured the infrared heat radiation from the surface at wavelengths between 9 and 16.5 microns within each of the 10 squares shown here. Each square is 6 kilometers (4 miles) across. The color of each square, and the number shown above it, describe the composite infrared spectrometer's measurement of the approximate average temperature of the surface within that square. The warmest temperature squares, at 91 and 89 degrees Kelvin (minus 296 and minus 299 degrees Fahrenheit), are located over one of the "tiger stripe" fractures. They contrast sharply with the surrounding temperatures, which are in the range 74 to 81 degrees Kelvin (minus 326 to minus 313 degrees Fahrenheit). The detailed composite infrared spectrometer data suggest that small areas near the fracture are at substantially higher temperatures, well over 100 degrees Kelvin (minus 279 degrees Fahrenheit). Such "warm" temperatures are unlikely to be due to heating of the surface by the feeble sunlight striking Enceladus' south pole. They are a strong indication that internal heat is leaking out of Enceladus and warming the surface along these fractures. Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. Scientists are unsure how the internal heat reaches the surface. The process might involve liquid water, slushy brine, or soft but solid ice. The imaging science subsystem image is an enhanced color view with a pixel scale of 122 meters (400 feet) that was acquired at the same time as the composite infrared spectrometer data. It covers a region 125 kilometers (75 miles) across. The spacecraft's distance from Enceladus was 21,000 kilometers (13,000 miles). The broad bluer fractures that can be seen running from the upper left to the lower right of the image are 1 to 2 kilometers (0.6 to 1.2 miles) wide and more than 100 kilometers (60 miles) long. The fractures are thought to be bluer than the surrounding surface because coarser-grained ice (which has a blue color just as thick masses of ice, like glaciers and icebergs, do on Earth) has been exposed in the fractures. The color image was constructed using an ultraviolet filter (centered at 338 nanometers) in the blue channel, a clear filter in the green channel, and an infrared filter (centered at 930 nanometers) in the red channel. The Cassini-Huygens mission is a cooperative project of NASA,, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/ . The imaging team homepage is at http://ciclops.org . Credit: NASA/JPL/GSFC/Space Science Institute |
| Date |
July 29, 2005 |
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Enceladus Temperature Map
| Description |
Enceladus Temperature Map |
| Full Description |
This image shows the surprise that startled Cassini scientists on the composite infrared spectrometer team when they got their first look at the infrared (heat) radiation from the south pole of Saturn's moon Enceladus. There is a dramatic warm spot centered on the pole that is probably a sign of internal heat leaking out of the icy moon. The data were taken during the spacecraft's third flyby of this intriguing moon on July 14, 2005. Based on data from previous flybys, which did not show the south pole well, team members expected that the south pole would be very cold, as shown in the left panel. Enceladus is one of the coldest places in the Saturn system because its extremely bright surface reflects 80 percent of the sunlight that hits it, so only 20 percent is available to heat the surface. As on Earth, the poles should be even colder than the equator because the sun shines at such an oblique angle there. The right hand panel shows a global temperature image made from measurements of Enceladus' heat radiation at wavelengths between 9 and 16.5 microns. Cassini made the observation from a distance of 84,000 kilometers (52,000 miles) on the approach to Enceladus, and the image shows details as small as 25 kilometers (16 miles). Equatorial temperatures are much as expected, topping out at about 80 degrees Kelvin (-315 degrees Fahrenheit), but the south pole is occupied by a well-defined warm region reaching 85 Kelvin (-305 degrees Fahrenheit). That is 15 degrees Kelvin (27 degrees Fahrenheit) warmer than expected. The composite infrared spectrometer data further suggest that small areas of the pole are at even higher temperatures, well over 110 degrees Kelvin (-261 degrees Fahrenheit). Evaporation of this relatively warm ice probably generates the cloud of water vapor detected above Enceladus' south pole by several other Cassini instruments. The south polar temperatures are very difficult to explain if sunlight is the only energy source heating the surface, though exotic sunlight-trapping mechanisms have not yet been completely ruled out. It therefore seems likely that portions of the polar region are warmed by heat escaping from the interior of the moon. This would make Enceladus only the third solid body in the solar system, after Earth and Jupiter's volcanic moon Io, where hot spots powered by internal heat have been detected. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The composite infrared spectrometer team homepage is, http://cirs.gsfc.nasa.gov/ . Credit: NASA/JPL/GSFC |
| Date |
July 29, 2005 |
|
Phoebe's Radiation
| Description |
Phoebe's Radiation |
| Full Description |
This image shows thermal radiation from the day and night sides of Saturn's moon Phoebe, taken by the composite infrared spectrometer onboard Cassini 1.8 hours before the spacecraft's closest approach to Phoebe on June 11, 2004. The left-hand panel displays the image in grayscale format, showing the brightness of Phoebe's radiation in the wavelength range 15-17 microns, which is about 25 times the longest wavelength visible to the naked eye. In the middle panel this brightness is used to estimate the surface temperature distribution across Phoebe. Temperatures are given in degrees Kelvin, and vary from a relatively toasty 107 Kelvin (-267 Fahrenheit), in the late morning near the equator (white, lower right), to less than 75 Kelvin (-324 Fahrenheit) in the northern hemisphere in the pre-dawn hours (dark blue, upper left). The "ragged edge" of Phoebe in this region is an instrumental artifact. Temperatures are affected strongly by topography, as can be seen by comparison with the visible-wavelength image (right). Some of the coldest temperatures are found in the shadowed region inside the large depression in the northern hemisphere (upper right). The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini composite infrared spectrometer home page at http://cirs.gsfc.nasa.gov/ . Image Credit: NASA/JPL/Goddard Space Flight Center |
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Atlas Found!
| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
The Cassini spacecraft has sighted the tiny moon Atlas, which is seen here for the first time since Voyager 1 flew past Saturn in 1980. Cassini's narrow angle camera captured a sequence of 112 images in visible light, which were used to create a movie of Atlas and other moons racing around the outer edge of Saturn's rings. One of those images is shown here. Over the course of almost five and one-quarter hours, Cassini watched the moons as they circled the planet, snapping 1.2-second exposures about 12 minutes apart. These images were part of a sequence designed specifically to search for small moons near Saturn's F ring. Contrast was enhanced in the images, and the rings themselves were overexposed intentionally, to make these small moons visible. A group of three moons can be seen rounding the right loop of Saturn's rings, followed by a fourth moon. In the first group, the moon exterior to Saturn's thin, knotted F ring is Epimetheus (116 kilometers, 72 miles across), the two moons interior to the F ring are Prometheus (102 kilometers, 63 miles across) and tiny unresolved Atlas (32 kilometers, 20 miles across). The fourth moon seen here, exterior to the F ring and tagging along behind the others, is Pandora (84 kilometers, 52 miles across). At the same time, on the left side, Janus can be seen (181 kilometers, 113 miles across). The view is taken looking upward from Cassini's southern vantage point beneath the ring plane. The moons visible here are orbiting Saturn in a plane that is tilted 67 degrees away from the viewer. These images were taken on May 26 and 27, 2004, from a distance of approximately 19.2 million kilometers (11.9 million miles) from Saturn. The image scale is approximately 114 kilometers (71 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org . Image Credit: NASA/JPL/Goddard Space Flight Center |
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Phoebe Temperature Maps
| Description |
Phoebe Temperature Maps |
| Full Description |
A montage of maps of Saturn's moon Phoebe shows surface temperatures at various times of day as determined by the composite infrared spectrometer onboard Cassini during the June 11, 2004, Phoebe flyby. The asterisk on each map shows the location of the subsolar point, where the Sun is directly overhead. This point moves across the surface as Phoebe rotates. It is morning in regions to the left of the subsolar point, and afternoon in regions to the right. Like a newspaper weather map, different colors indicate different temperatures, though Phoebe's temperatures are distinctly cooler than even the coldest January day on Earth. Equatorial temperatures peak in the early afternoon near 112 Kelvin (-257 Fahrenheit), plunging to 78 Kelvin (-319 Fahrenheit) before dawn, and are even colder at higher latitudes. The large day/night temperature contrasts imply that Phoebe's surface is covered in loose dust or ice particles that store little heat and thus cool off rapidly at night. Regions of Phoebe's surface that were not observed are shown in black. Most of the maps show the effect on surface temperatures of the large crater-like depression seen in Cassini's visible-wavelength images of Phoebe, which is located just left of center in these maps. Crater walls that are shadowed and cold in the early morning in the first map are sunlit and warm in the late afternoon in the final map. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini composite infrared spectrometer home page at http://cirs.gsfc.nasa.gov/ . Image Credit: NASA/JPL/Goddard Space Flight Center |
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Slower Spinning Rings #1
| Description |
Slower Spinning Rings #1 |
| Full Description |
The Cassini composite infrared spectrometer obtained temperature maps of Saturn's main rings (A, B and C) that showed ring temperatures decreasing with increasing solar phase angle (the change of the sun-spacecraft-ring angle) on both the lit and unlit sides of the rings. Temperature changes throughout Saturn's main rings, as measured by the instrument, indicate that Saturn ring particles spin slowly compared to their orbital periods of 6 to 14 hours. They may spin several times per orbit to less than one time per orbit. Scans are shown for the lit and unlit rings, at relatively low (less than 60-degree) and high (more than 130-degree) phase angles. Each scan was painted on the rings at the correct ring orientation, creating a false color image. Warmer temperatures about minus 262 degrees Fahrenheit (110 Kelvin) are shown in red and cooler temperatures about minus 343 degrees (65 K) are shown in blue. Other colors indicate temperatures between minus 343 degrees and minus 262 degrees (65 K and 110 K). The scans of the lit rings are shown in the two panels on the left and scans of the unlit rings are shown in the two panels on the right. The thermal characteristics of each main ring vary noticeably with phase angle. Radial scans of the A, B and C rings show a decrease in temperature with increasing phase angle for both the lit and unlit sides of the rings. The C ring and Cassini Division exhibit the largest change in temperature. The temperature of the lit C ring decreases by about 22 degrees (12 Kelvin) between low and high phase angles. A similar contrast is present for the unlit side of the C ring. The C ring and Cassini Division are darker than the A and B rings so they can absorb more heat from the Sun. The lit B ring shows a temperature contrast of approximately 18 degrees (10 K) while the unlit B ring shows very little thermal contrast. Very little sunlight may make it through the thick B ring to its unlit side. The lit A ring is particularly interesting because the magnitude of the thermal contrast decreases with increasing radial distance from Saturn. The outer A ring shows only a small temperature change with phase angle, possibly because it contains smaller, or more rapidly rotating ring particles, which would have more uniform temperatures with phase angle. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. Credit: NASA/JPL/GSFC |
| Date |
September 5, 2005 |
|
Slower Spinning Rings #2
| Description |
Slower Spinning Rings #2 |
| Full Description |
Temperature changes mapped with Cassini's composite and infrared spectrometer throughout Saturn's main rings show the ring temperatures decreasing with the increase of the Sun-spacecraft-ring angle (called phase angle) on both the lit and unlit sides of the rings. These temperature changes indicate that the ring particles spin slowly compared to their orbital periods of 6 to 14 hours. They may spin several times per orbit to less than one time per orbit. Four scans are shown for the lit and unlit rings, at relatively low (less than 60 degrees) and high (more than 130 degrees) phase angles. Warmer temperatures about minus 262 degrees Fahrenheit (110 Kelvin) are shown in red and cooler temperatures about minus 343 degrees (65 K) are shown in blue. Other colors indicate temperatures between minus 343 degrees and minus 262 degrees (65 K and 110 K). The top two scans are for the lit rings and the bottom two scans are for the unlit rings. The change in ring temperature between each scan can be seen clearly. The thermal characteristics of each main ring vary noticeably with phase angle. Radial scans of the A, B and C rings show a decrease in temperature with increasing phase angle for both the lit and unlit sides of the rings. The C ring and Cassini Division exhibit the largest change in temperature. The temperature of the lit C ring decreases by about 22 degrees (12 Kelvin) between low and high phase angles. A similar contrast is present for the unlit side of the C ring. The C ring and Cassini Division are darker than the A and B rings so they can absorb more heat from the Sun. The lit B ring shows a temperature contrast of approximately 18 degrees (10 K) while the unlit B ring shows very little thermal contrast. Very little sunlight may make it through the thick B ring to its unlit side. The lit A ring is particularly interesting because the magnitude of the thermal contrast decreases with increasing radial distance from Saturn. The outer A ring shows only a small temperature change with phase angle, possibly because it contains smaller, or more rapidly rotating ring particles, which would have more uniform temperatures with phase angle. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. |
| Date |
September 5, 2005 |
|
Iapetus Temperature Map
| Description |
Iapetus Temperature Map |
| Full Description |
This temperature map of Saturn's moon Iapetus is constructed from observations of Iapetus's infrared heat radiation taken with the Cassini composite infrared spectrometer instrument during the Dec. 31, 2004 flyby. The orange asterisk marks the point on Iapetus where the Sun is directly overhead. Temperatures reach nearly 130 Kelvin (-226 Fahrenheit) at noon on the equator on the dark material that covers most of this side of Iapetus, making high noon on Iapetus's dark side probably the warmest places in the Saturn system. This is much warmer than temperatures on the moon Phoebe measured by the composite infrared spectrometer in June 2004, which peaked near 112 Kelvin (-258 Fahrenheit). That's because, although Phoebe is almost as dark as Iapetus's dark material and absorbs nearly as much sunlight, Phoebe rotates much more quickly (once every 9 hours, compared to 79 days for Iapetus). That means the surface has less time to heat up during the day. Temperatures on Iapetus' bright material are much colder, peaking near 100 Kelvin (-280 Fahrenheit), both because the bright material absorbs less sunlight and because it is further from the equator on this side of Iapetus. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. For more information about the Cassini-Huygens mission visit, http://saturn.jpl.nasa.gov and the instrument team's home page, http://cirs.gsfc.nasa.gov/. *Credit*: NASA/JPL/GSFC |
| Date |
January 10, 2005 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by the composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is most strongly seen in the left-most composite infrared spectrometer field of view, which includes a fissure near the end of one of the tiger stripes. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07794) for a related image. This image is centered near longitude 135 west, latitude 65 south, and each square from the composite infrared spectrometer field of view is 17.5 kilometers (10.9 miles) across. This Cassini narrow-angle camera image has been cropped and resized for presentation. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Searching for Warmth
| Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. |
| Full Description |
The exciting mystery of an active south polar region on Saturn's icy moon Enceladus continues to unfold as scientists make the correlation between geologically youthful surface fractures and unusually warm temperatures. This view shows excess heat radiation from cracks near the moon's south pole. These warm fissures are the source of plumes of dust and gas seen by multiple instruments on the Cassini spacecraft during its flyby of Enceladus on July 14, 2005, as described in a series of papers in the March 10, 2006, issue of the journal Science. This image shows two arrays of temperature readings across the surface of Enceladus, as measured by the Cassini composite infrared spectrometer, superimposed on images of the surface taken simultaneously by the imaging science subsystem. Surface temperatures in Kelvin, derived from the intensity of infrared radiation detected by composite infrared spectrometer, are shown along with their formal uncertainties, although true uncertainties for temperatures below about 75 Kelvin (minus 325 degrees Fahrenheit) are not easily described by a single number. Enhanced thermal emission is seen in the vicinity of the prominent "tiger stripe" fissures discovered by the imaging cameras. In this image, the excess emission is near the center of the composite infrared spectrometer array, directly over a tiger stripe fissure. The peak temperatures, 86 Kelvin and 90 Kelvin (minus 305 and minus 298 degrees Fahrenheit) respectively, are averages over the composite infrared spectrometer field of view, and other composite and infrared spectrometer data suggest that much higher temperatures, up to at least 145 Kelvin (minus 199 degrees Fahrenheit), occur in narrow zones a few hundred meters wide along the tiger stripe fissures. See (PIA07793) for a related image. This image was taken nearly three times closer to the moon and is centered near longitude 120 west, latitude 82 south, and each composite infrared spectrometer field of view is 6.0 kilometers (3.7 miles) across. This Cassini narrow-angle camera image was cropped and resized for presentation. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The composite infrared spectrometer team homepage is http://cirs.gsfc.nasa.gov/. The imaging team homepage is at http://ciclops.org *Credit:* NASA/JPL/GSFC/Space Science Institute |
| Date |
March 9, 2006 |
|
Zoom into NASA's Goddard Spa
…
| Title |
Zoom into NASA's Goddard Space Flight Center, using Landsat Imagery (WMS) |
| Abstract |
The WMS Global Mosaic dataset was developed at NASA's Jet Propulstion Laboratory (JPL). This global mosaic was produced from visual and near infrared bands taken by the Landsat-7 satellite. Using the panchromatic band to sharpen the final image, a final resolution of 0.5 arc seconds (about 15 meters) can be achieved. This mosaic is available through the Web Mapping Services (WMS) protocol at JPL. This series of images was obtained using a software program called the Digital Earth PC which can use the WMS protocol to obtain images covering an arbitrary region of the earth. These images can be arranged in such a way with the Digital Earth PC software that a nearly continuous zoom effect can be achieved. |
| Completed |
2004-10-21 |
|
Zoom into NASA's Goddard Spa
…
| Title |
Zoom into NASA's Goddard Space Flight Center, using Landsat Imagery (WMS) |
| Abstract |
The WMS Global Mosaic dataset was developed at NASA's Jet Propulstion Laboratory (JPL). This global mosaic was produced from visual and near infrared bands taken by the Landsat-7 satellite. Using the panchromatic band to sharpen the final image, a final resolution of 0.5 arc seconds (about 15 meters) can be achieved. This mosaic is available through the Web Mapping Services (WMS) protocol at JPL. This series of images was obtained using a software program called the Digital Earth PC which can use the WMS protocol to obtain images covering an arbitrary region of the earth. These images can be arranged in such a way with the Digital Earth PC software that a nearly continuous zoom effect can be achieved. |
| Completed |
2004-10-21 |
|
A Spaceborne Perspective on
…
| Title |
A Spaceborne Perspective on the Red, White, and Blue |
| Description |
Philadelphia, where the Declaration of Independence was signed 225 years ago on July 4, 1776, lies in the center of this image from NASA's Multi-angle Imaging SpectroRadiometer (MISR). This true-color view of the northeastern United States, taken from the instrument's nadir, or downward-looking, camera includes a fitting display of the reddish colors of soils, grayish-whites of urban areas and clouds, and blue hues of water. Larger cities, including New York, Newark, Philadelphia, Wilmington, Baltimore and Washington D.C., are visible from upper right to lower left. The bright sands of the New Jersey shoreline and a pattern of highly reflective roads and bridges extend northward along the coast from Delaware Bay. A popular tourist destination for those wanting to avoid the crowds and main roads is the Coastal Heritage Trail, a 440-kilometer collection of historic and other points of interest developed by the National Park Service and the state of New Jersey. A portion of Pennsylvania's Appalachian Mountains are captured in the upper left corner. The effects of folding and erosion on these ancient, mostly sedimentary deposits are visible, and the reddish colors indicate ironstone and iron-rich sandstone. The southeast-flowing Susquehanna River cuts transversely across these folded formations toward the Chesapeake Bay in Havre de Grace, Maryland, where it provides 50 percent of all the freshwater entering the great estuary. The waters of the Susquehanna originate at Otsego Lake in New York and meander along 700 kilometers until reaching Chesapeake Bay and the sea. This image was acquired on October 11, 2000. It covers an area 334 kilometers x 328 kilometers. North is at the top. Image credit: NASA/GSFC/LaRC/JPL, MISR Team. [ http://www-misr.jpl.nasa.gov/ ] |
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A Summer View of Russia's Le
…
| Title |
A Summer View of Russia's Lena Delta and Olenek River |
| Description |
These views of the Russian Arctic were acquired by NASA's Multi-angle Imaging SpectroRadiometer (MISR) instrument on July 11, 2004. The brief arctic summer had transformed the frozen tundra and the thousands of lakes, channels, and rivers of the Lena Delta into a fertile wetland, and the usual blanket of thick snow had melted from the vast plains and taiga forests. The images show an area in the northern part of the Sakha Republic in eastern Siberia. The Olenek River wends northeast from the bottom of the images to the upper left, and the delta through which the mighty Lena River empties into the Laptev Sea dominate the top portions of the images. Creating accurate maps of vegetation structure is essential for understanding the seasonal exchanges of energy and water at the Earth's surface and for preserving biodiversity. The left-hand image is a natural-color image from MISR's nadir (vertical-viewing) camera, in which the rivers appear murky due to sediment, and photosynthetically active vegetation appears green. The center image is also from MISR's nadir camera, but is a false-color view in which the predominant red color is due to the brightness of vegetation at near-infrared wavelengths. Apart from the Lena Delta, the most photosynthetically active regions are within the lower half of the image and throughout the great stretch of land that curves across the Olenek River.  The relatively barren ranges of the Volyoi Mountains appear as the pale tan-colored area to the right of image center. The right-hand image is a multiangle, false-color view made from the red band data of the 60-degree-backward, nadir, and 60-degree-forward cameras, displayed as red, green and blue, respectively. Water appears blue in this image because sun glint makes smooth, wet surfaces look brighter at the forward camera's view angle. Much of the landscape and many low clouds appear purple because these surfaces are both forward and backward scattering, and clouds that are further from the surface appear in a different spot for each view angle, creating a rainbow-like appearance. The highly vegetated region in the natural-color nadir image exhibits a faint greenish hue in the multi-angle composite. This subtle effect suggests that the nadir camera is observing more of the brighter, underlying surface than the oblique cameras, providing information about the distribution and density of trees and shrubs in this area. The Multiangle Imaging SpectroRadiometer observes the daylit Earth continuously, and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. The MISR Browse Image Viewer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://eosweb.larc.nasa.gov/MISRBR/ ], provides access to low-resolution true-color versions of these images. These data products were generated from a portion of the imagery acquired during Terra orbit 24273. The panels cover an area of about 230 kilometers x 420 kilometers, and utilize data from blocks 30 to 34 within World Reference System-2 path 134. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Raytheon/JPL). |
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Cloud Heights of Frances and
…
| Title |
Cloud Heights of Frances and Ivan |
| Description |
NASA's Multi-angle Imaging SpectroRadiometer [ http://www-misr.jpl.nasa.gov ] (MISR) captured these images and cloud-top height retrievals of Hurricane Frances on September 4, 2004, when the eye sat just off the coast of eastern Florida, and Hurricane Ivan on September 5, after the storm had devastated Grenada and was heading toward the central and western Caribbean. Hurricane Frances made landfall in the early hours of September 5, and was downgraded to Tropical Storm status as it swept inland through the Florida panhandle and continued northward. Following on the heels of Frances is Hurricane Ivan, which is on record as the strongest tropical hurricane to form at such a low latitude in the Atlantic, and was the most powerful storm to have hit the Caribbean in nearly a decade. The ability of forecasters to predict the intensity and amount of rainfall associated with hurricanes still requires improvement, especially on the 24- to 48-hour timescale vital for disaster planning. To improve the operational models used to make hurricane forecasts, scientists need to better understand the multi-scale interactions at the cloud, mesoscale and synoptic scales that lead to hurricane intensification and dissipation, as well as the various physical processes that determine hurricane intensity and rainfall distributions. Because these uncertainties with regard to how to represent cloud processes still exist, it is vital that the model findings be evaluated against hurricane observations whenever possible. Two-dimensional maps of cloud height such as those shown here offer an unprecedented opportunity for comparing simulated cloud fields against actual hurricane observations. The lefthand panel in each image pair is a natural-color view from MISR's nadir camera. The righthand panels are cloud-top height retrievals produced by automated computer recognition of the distinctive spatial features between images acquired at different view angles. These results indicate that at the time that these images were acquired, clouds within Frances and Ivan had attained altitudes of 15-16 kilometers (9-10 miles) above sea level, respectively. The height fields pictured here are uncorrected for the effects of cloud motion. Wind-corrected heights (which have higher accuracy but coarser spatial coverage) are within about 1 kilometer of the heights shown here. (Visit the Earth Observatory's Natural Hazards Severe Storms [ http://earthobservatory.nasa.gov/NaturalHazards/natural_hazards_v2.php3?topic=storm ] section to view more recent images of Hurricanes Ivan and Frances.) The MISR observes the daylit Earth continuously and every 9 days views the entire globe between 82° north and 82° south latitude. These data products were generated from a portion of the imagery acquired during Terra [ http://terra.nasa.gov ], orbits 25081 and 25094. The panels cover an area of 380 kilometers x 924 kilometers, and utilize data from within blocks 65 to 87 within World Reference System-2 paths 14 and 222, respectively. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. NASA image courtesy GSFC/LaRC/JPL, MISR Team. [ http://www-misr.jpl.nasa.gov ] Text acknowledgment: Clare Averill (Raytheon/Jet Propulsion Laboratory) and Greg McFarquhar (University of Illinois at Urbana-Champaign). |
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Hurricane Katrina
| Title |
Hurricane Katrina |
| Description |
Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology. Images and movie courtesy of NASA/GSFC/LaRC/JPL, MISR Team. Caption details provided by Clare Averill (Raytheon ITSS/Jet Propulsion Laboratory), David J. Diner, Mike Garay and Ralph Kahn (Jet Propulsion Laboratory) and Greg McFarquhar (University of Illinois at Urbana-Champaign)., MISR stereo-height estimates (not shown here) indicate that the highest clouds reach 18-19 kilometers above the surface of the Earth. The stereo anaglyph shows relative height variations and enhances the appearance of thin clouds, such as those that mark the series of gravity waves north-east of the eyewall. Atmospheric gravity waves are caused by air displacements in an otherwise stable air layer. In this case, the gravity waves are above the hurricane arms in the upper troposphere, and were probably generated as the towering storm updraft tried to push into the stable air between the troposphere and the stratosphere (known as the tropopause). Some of Katrina's cloud tops were about 2 kilometers above the tropopause. Such high "overshooting tops" are also characteristic of strong and rapidly growing storms. The animation progresses from MISR's most forward-pointing camera, which views the scene first, to the most backward-pointing camera, which views the scene last. It was created by aligning the views from all 9 cameras using the high clouds within the eyewall as a reference point. North is at the top. The convective cloud towers, especially those along the eastern sides of the inner and outer eyewalls, attain the highest altitudes and indicate that the storm is strengthening. Those areas that do not exhibit cloud-top convection are clouds experiencing vertical wind shear, and tend to be lower than the towering cloud structures. The vertical and horizontal development of the convective clouds and the formation of an outer ring of growing clouds (referred to as an "eyewall replacement cycle") also indicate rapid strengthening. During this stage of hurricane development, an outer band of clouds may gradually move inward to replace the existing hurricane eyewall, causing the central pressure to increase and weaken the storm in the short term. However, eyewall replacement may sometimes be a forerunner for rapid strengthening in the longer term. This was the case with Hurricane Katrina, whose central pressure increased slightly on Saturday, but then dropped again significantly on Sunday when Katrina became a Category 5 storm. Observing the development of a concentric eyewall at this spatial and temporal resolution is a unique feature of these MISR observations. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82 degrees North and 82 degrees South latitude every nine days. The still images each cover an area of about 827 kilometers by 380 kilometers, and the animation covers an area of about 202 kilometers by 214 kilometers. The data products were generated from a portion of the imagery acquired during Terra orbit 30280 and utilize data from blocks 69 to 74 within World Reference System-2 path 17. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's, This image and animation from NASA's Multi-angle Imaging SpectroRadiometer (MISR) show the strong convective development of Hurricane Katrina on Saturday, August 27, as it moved west through the Gulf of Mexico. Over 7 minutes during which all 9 MISR cameras viewed Katrina, the animation captures the cloud-top sides, the counterclockwise rotation of the eyewall, and the bubbling growth of the towering cloud structures. At this time, Katrina was undergoing rapid development— it had just been upgraded to a Category 3 hurricane, and within 24 hours it would reach Category 5. On Monday morning when the eyewall made landfall over the United States, it was a Category 4 storm. Hurricane Katrina was one of the most powerful and destructive storms on record for the Atlantic Basin. The image above is a false-color view (near-infrared, red, and blue wavelengths of reflected light displayed as red, green and blue) from MISR's nadir (pointing straight down) camera. In the image above, north is up. The high resolution image linked above shows a wider view of this false-color image, with north to the left. The vegetated Alabama coast in the upper left-hand corner in this high-resolution image appears in red hues. The bottom panel in the high-resolution image is a 3-D stereo anaglyph created with red band data from MISR's 70-degree-forward-viewing and 60-degree-forward-viewing cameras, displayed as red and green/blue, respectively. To observe the height variations in 3-D, you will need to use red/blue glasses. [ http://photojournal.jpl.nasa.gov/Help/VendorList.html#Glasses ] |
|
Hurricane Katrina
| Title |
Hurricane Katrina |
| Description |
Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology. Images and movie courtesy of NASA/GSFC/LaRC/JPL, MISR Team. Caption details provided by Clare Averill (Raytheon ITSS/Jet Propulsion Laboratory), David J. Diner, Mike Garay and Ralph Kahn (Jet Propulsion Laboratory) and Greg McFarquhar (University of Illinois at Urbana-Champaign)., MISR stereo-height estimates (not shown here) indicate that the highest clouds reach 18-19 kilometers above the surface of the Earth. The stereo anaglyph shows relative height variations and enhances the appearance of thin clouds, such as those that mark the series of gravity waves north-east of the eyewall. Atmospheric gravity waves are caused by air displacements in an otherwise stable air layer. In this case, the gravity waves are above the hurricane arms in the upper troposphere, and were probably generated as the towering storm updraft tried to push into the stable air between the troposphere and the stratosphere (known as the tropopause). Some of Katrina's cloud tops were about 2 kilometers above the tropopause. Such high "overshooting tops" are also characteristic of strong and rapidly growing storms. The animation progresses from MISR's most forward-pointing camera, which views the scene first, to the most backward-pointing camera, which views the scene last. It was created by aligning the views from all 9 cameras using the high clouds within the eyewall as a reference point. North is at the top. The convective cloud towers, especially those along the eastern sides of the inner and outer eyewalls, attain the highest altitudes and indicate that the storm is strengthening. Those areas that do not exhibit cloud-top convection are clouds experiencing vertical wind shear, and tend to be lower than the towering cloud structures. The vertical and horizontal development of the convective clouds and the formation of an outer ring of growing clouds (referred to as an "eyewall replacement cycle") also indicate rapid strengthening. During this stage of hurricane development, an outer band of clouds may gradually move inward to replace the existing hurricane eyewall, causing the central pressure to increase and weaken the storm in the short term. However, eyewall replacement may sometimes be a forerunner for rapid strengthening in the longer term. This was the case with Hurricane Katrina, whose central pressure increased slightly on Saturday, but then dropped again significantly on Sunday when Katrina became a Category 5 storm. Observing the development of a concentric eyewall at this spatial and temporal resolution is a unique feature of these MISR observations. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82 degrees North and 82 degrees South latitude every nine days. The still images each cover an area of about 827 kilometers by 380 kilometers, and the animation covers an area of about 202 kilometers by 214 kilometers. The data products were generated from a portion of the imagery acquired during Terra orbit 30280 and utilize data from blocks 69 to 74 within World Reference System-2 path 17. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's, This image and animation from NASA's Multi-angle Imaging SpectroRadiometer (MISR) show the strong convective development of Hurricane Katrina on Saturday, August 27, as it moved west through the Gulf of Mexico. Over 7 minutes during which all 9 MISR cameras viewed Katrina, the animation captures the cloud-top sides, the counterclockwise rotation of the eyewall, and the bubbling growth of the towering cloud structures. At this time, Katrina was undergoing rapid development— it had just been upgraded to a Category 3 hurricane, and within 24 hours it would reach Category 5. On Monday morning when the eyewall made landfall over the United States, it was a Category 4 storm. Hurricane Katrina was one of the most powerful and destructive storms on record for the Atlantic Basin. The image above is a false-color view (near-infrared, red, and blue wavelengths of reflected light displayed as red, green and blue) from MISR's nadir (pointing straight down) camera. In the image above, north is up. The high resolution image linked above shows a wider view of this false-color image, with north to the left. The vegetated Alabama coast in the upper left-hand corner in this high-resolution image appears in red hues. The bottom panel in the high-resolution image is a 3-D stereo anaglyph created with red band data from MISR's 70-degree-forward-viewing and 60-degree-forward-viewing cameras, displayed as red and green/blue, respectively. To observe the height variations in 3-D, you will need to use red/blue glasses. [ http://photojournal.jpl.nasa.gov/Help/VendorList.html#Glasses ] |
|
Hurricane Katrina
| Title |
Hurricane Katrina |
| Description |
Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology. Images and movie courtesy of NASA/GSFC/LaRC/JPL, MISR Team. Caption details provided by Clare Averill (Raytheon ITSS/Jet Propulsion Laboratory), David J. Diner, Mike Garay and Ralph Kahn (Jet Propulsion Laboratory) and Greg McFarquhar (University of Illinois at Urbana-Champaign)., MISR stereo-height estimates (not shown here) indicate that the highest clouds reach 18-19 kilometers above the surface of the Earth. The stereo anaglyph shows relative height variations and enhances the appearance of thin clouds, such as those that mark the series of gravity waves north-east of the eyewall. Atmospheric gravity waves are caused by air displacements in an otherwise stable air layer. In this case, the gravity waves are above the hurricane arms in the upper troposphere, and were probably generated as the towering storm updraft tried to push into the stable air between the troposphere and the stratosphere (known as the tropopause). Some of Katrina's cloud tops were about 2 kilometers above the tropopause. Such high "overshooting tops" are also characteristic of strong and rapidly growing storms. The animation progresses from MISR's most forward-pointing camera, which views the scene first, to the most backward-pointing camera, which views the scene last. It was created by aligning the views from all 9 cameras using the high clouds within the eyewall as a reference point. North is at the top. The convective cloud towers, especially those along the eastern sides of the inner and outer eyewalls, attain the highest altitudes and indicate that the storm is strengthening. Those areas that do not exhibit cloud-top convection are clouds experiencing vertical wind shear, and tend to be lower than the towering cloud structures. The vertical and horizontal development of the convective clouds and the formation of an outer ring of growing clouds (referred to as an "eyewall replacement cycle") also indicate rapid strengthening. During this stage of hurricane development, an outer band of clouds may gradually move inward to replace the existing hurricane eyewall, causing the central pressure to increase and weaken the storm in the short term. However, eyewall replacement may sometimes be a forerunner for rapid strengthening in the longer term. This was the case with Hurricane Katrina, whose central pressure increased slightly on Saturday, but then dropped again significantly on Sunday when Katrina became a Category 5 storm. Observing the development of a concentric eyewall at this spatial and temporal resolution is a unique feature of these MISR observations. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82 degrees North and 82 degrees South latitude every nine days. The still images each cover an area of about 827 kilometers by 380 kilometers, and the animation covers an area of about 202 kilometers by 214 kilometers. The data products were generated from a portion of the imagery acquired during Terra orbit 30280 and utilize data from blocks 69 to 74 within World Reference System-2 path 17. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's, This image and animation from NASA's Multi-angle Imaging SpectroRadiometer (MISR) show the strong convective development of Hurricane Katrina on Saturday, August 27, as it moved west through the Gulf of Mexico. Over 7 minutes during which all 9 MISR cameras viewed Katrina, the animation captures the cloud-top sides, the counterclockwise rotation of the eyewall, and the bubbling growth of the towering cloud structures. At this time, Katrina was undergoing rapid development— it had just been upgraded to a Category 3 hurricane, and within 24 hours it would reach Category 5. On Monday morning when the eyewall made landfall over the United States, it was a Category 4 storm. Hurricane Katrina was one of the most powerful and destructive storms on record for the Atlantic Basin. The image above is a false-color view (near-infrared, red, and blue wavelengths of reflected light displayed as red, green and blue) from MISR's nadir (pointing straight down) camera. In the image above, north is up. The high resolution image linked above shows a wider view of this false-color image, with north to the left. The vegetated Alabama coast in the upper left-hand corner in this high-resolution image appears in red hues. The bottom panel in the high-resolution image is a 3-D stereo anaglyph created with red band data from MISR's 70-degree-forward-viewing and 60-degree-forward-viewing cameras, displayed as red and green/blue, respectively. To observe the height variations in 3-D, you will need to use red/blue glasses. [ http://photojournal.jpl.nasa.gov/Help/VendorList.html#Glasses ] |
|
Mount St. Helens Flyover
| Title |
Mount St. Helens Flyover |
| Description |
This Advanced Spaceborne Thermal Emission and Reflection Radiometer [ http://earthobservatory.nasa.gov/cgi-bin/redirect?http://asterweb.jpl.nasa.gov/ ] (ASTER) image of Mt. St. Helens volcano in Washington State was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER?s 3-D stereo bands. The color was computer enhanced to create a ?natural? color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief. Landsat7 aquired an image of Mt. St. Helens [ http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=3321 ] on August 22, 1999. Image and animation courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. |
|
Rice Cultivation in Northwes
…
| Title |
Rice Cultivation in Northwest Italy |
| Description |
The lowlands of Lombardy and Piedmont in northwest Italy are some of the most highly developed irrigation areas in the world. Irrigated lands cover at least 160,000 acres in this part of Italy, where rice is the most important crop. These views of the region were acquired on May 8, 2005, by NASA's Multi-angle Imaging SpectroRadiometer (MISR). The multiple viewing angles provided by MISR's nine cameras make it possible to tell wet surfaces, including flooded lands, from other surfaces, and they also make cities easy to locate. The left-hand image is a natural-color view acquired by MISR's downward-looking (nadir) camera, and the right-hand image is a combination of red band data from MISR's 60-degree-backward-, nadir, and 60-degree-forward-viewing cameras. (Red band is what scientists call the "channel" on the sensor that detects red light.) Color changes indicate surface texture, which is influenced by terrain, vegetation structure, soil type, and surface wetness. Wet surfaces or areas with standing water appear in blue or purple-blue hues. The purple-blue areas that dominate the center-left part of the image are part of the extensive irrigation network that exists throughout the plains and meadows of the region. Cities with tall buildings appear in red-orange hues. In this type of image, the city of Milan is the most obvious. The small orange area in the center of the purple inundated area indicates the location of Vercelli, and the larger city of Milan is the orange area to the northeast, on the other side of the Ticino River. To a lesser extent, the cities of Novara, Pavia, Galliate, Mortara, and Vigevano are also identifiable by their orange hues. MISR can tell various surface features like cities or irrigated areas apart because of the way surfaces reflect light. A smooth water surface tends to reflect sunlight away from the Sun. This effect is most apparent when a satellite views the surface with the Sun in front of the camera. Similarly, rough surfaces tend to reflect light back towards the Sun, and this "backward scattering" is most obvious when a satellites views a surface with the Sun behind the camera. Clouds present over the high country to the west of the Lago Maggiore (upper left corner) and along the coast of the Golfo di Genova (bottom) appear in a different spot for each view angle, creating a rainbow-like appearance. Mountains also have a "wavy" look in the multi-angle combination because, like clouds, their height above the surface makes them appear in a different spot in each camera's view angle. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously, viewing the entire globe between 82 degrees North and 82 degrees South latitude every nine days. This image covers an area of about 131 kilometers by 191 kilometers. These data products were generated from a portion of the imagery acquired during Terra orbit 28660 and utilize data from block 54 within World Reference System-2 path 193. MISR was, built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is managed for NASA by the California Institute of Technology. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. [ http://www-misr.jpl.nasa.gov/ ] Text by Clare Averill (Raytheon ITSS/JPL) |
|
Tropical Cyclone Monty
| Title |
Tropical Cyclone Monty |
| Description |
The Multi-angle Imaging SpectroRadiometer (MISR) acquired these natural color images and cloud top height measurements for Monty before and after the storm made landfall over the remote Pilbara region of Western Australia, on February 29 and March 2, 2004 (shown as the left and right-hand image sets, respectively). On February 29, Monty was upgraded to category 4 cyclone status. After traveling inland about 300 kilometers to the south, the cyclonic circulation had decayed considerably, although category 3 force winds were reported on the ground. Some parts of the drought-affected Pilbara region received more than 300 millimeters of rainfall, and serious and extensive flooding has occurred. The natural color images cover much of the same area, although the right-hand panels are offset slightly to the east. Automated stereoscopic processing of data from multiple MISR cameras was utilized to produce the cloud-top height fields. The distinctive spatial patterns of the clouds provide the necessary contrast to enable automated feature matching between images acquired at different view angles. The height retrievals are at this stage uncorrected for the effects of the high winds associated with cyclone rotation. Areas where heights could not be retrieved are shown in dark gray. The Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously and every 9 days views the entire globe between 82 degrees north and 82 degrees south latitude. These data products were generated from a portion of the imagery acquired during Terra orbits 22335 and 22364. The panels cover an area of about 380 kilometers x 985 kilometers, and utilize data from blocks 105 to 111 within World Reference System-2 paths 115 and 113. MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology. Image courtesy NASA/GSFC/LaRC/JPL MISR Team [ http://www-misr.jpl.nasa.gov/ ], caption courtesy Clare Averill, Raytheon/Jet Propulsion Laboratory. |
|
MyCn18: An Hourglass Nebula
| Title |
MyCn18: An Hourglass Nebula |
| Explanation |
The sands of time are running out for the central star of this hourglass-shaped planetary nebula [ http://fusedweb.pppl.gov/CPEP/ Chart_Pages/5.Plasmas/Nebula/Planetary.html ]. With its nuclear fuel [ http://fusedweb.pppl.gov/default.html ] exhausted, this brief, spectacular, closing phase of a Sun-like star's life [ http://observe.ivv.nasa.gov/nasa/space/stellardeath/stellardeath_contents.html ] occurs as its outer layers are ejected - its core becoming a cooling, fading White Dwarf [ http://antwrp.gsfc.nasa.gov/apod/ap971102.html ]. Astronomers have recently used the Hubble Space Telescope [ http://hubble.stsci.edu/ ] (HST) to make a series of images of planetary nebulae [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], including the one above [ http://www.stsci.edu/pubinfo/PR/96/07.html ]. Here, delicate rings of colorful glowing gas (nitrogen-red, hydrogen-green, and oxygen-blue) outline the tenuous walls of the "hourglass". The unprecedented sharpness of the HST images has revealed surprising details [ http://www.stsci.edu/pubinfo/gif/Hourgls.txt ] of the nebula ejection process [ http://antwrp.gsfc.nasa.gov/apod/ap960117.html ] and may help resolve the outstanding mystery of the variety of complex shapes and symmetries of planetary nebulae [ http://www.astro.washington.edu/balick/WFPC2/index.html ]. |
|
October Skylights
| Title |
October Skylights |
| Explanation |
With brilliant Venus [ http://nssdc.gsfc.nasa.gov/planetary/factsheet/ venusfact.html ] above the western horizon at sunset and Jupiter [ http://galileo.jpl.nasa.gov/ ] and Saturn [ http://www.jpl.nasa.gov/cassini/ ] high in the east by early evening, November's night sky is filled with bright planets. October's sky featured bright planets as well and, triggered by the active Sun, some lovely auroral displays [ http://www.exploratorium.edu/learning_studio/ auroras/ ]. This colorful aurora was recorded by astrophotographer Wade Clark in skies above Hamilton, Washington, USA on the night of October 4th. Through the shimmering northern lights [ http://climate.gi.alaska.edu/Curtis/aurora/ aurora.html ] Jupiter and Saturn are easy to spot [ http://antwrp.gsfc.nasa.gov/apod/ap000929.html ] flanking the V-shaped head of Taurus [ http://server.remc12.k12.mi.us/csplanet/myth/ taurus.html ] the Bull. Of course, just above lies the lovely Pleiades star cluster. Solar activity [ http://spaceweather.com/ ] will also produce auroral shows in November, particularly at high northern and southern latitudes. Plus, November skygazers can certainly anticipate a celestial performance on the evening of the 17th/18th -- the moonlit Leonid meteor shower [ http://spacescience.com/headlines/y2000/ast10oct_1.htm ]. |
|
Solar System Web Cam
| Title |
Solar System Web Cam |
| Explanation |
Ranging throughout the solar system [ http://space.jpl.nasa.gov/ ], these pictures all have something in common. They were taken with an 8 inch diameter telescope, a size popular with amateur astronomy buffs, and slightly modified "web cam" of the type widely used to send images out over the internet. The results are clearly remarkable for [ http://www.djcash.demon.co.uk/astro/webcam/webcam.htm ] such inexpensive and readily available equipment. Each sharp image was produced from 20 to 30 frames which were digitally stacked and processed using free software [ http://utopia.ision.nl/users/rjstek/english/software/ index.htm ]. Until recently, digital imaging for amateur astronomers required a specialized camera [ http://www.wvi.com/~rberry/cookbook.htm ], but the advent of low-light video surveillance cameras and web cams now presents other options for relatively bright [ http://www.astrabio.demon.co.uk/QCUIAG/ac/3dmoon.htm ] solar system objects. Want to try some unconventional [ http://www.astrabio.demon.co.uk/QCUIAG/ ] web cam astronomy? Geoff Chester, Public Affairs Officer at the U.S. Naval Observatory [ http://www.usno.navy.mil ], offers these images and an account of his own adventures [ http://www.usno.navy.mil/pao/QuickCamAstro.shtml ] from a suburban front lawn near Washington D.C. |
|
25 Years Ago: Vikings on Mar
…
| Title |
25 Years Ago: Vikings on Mars |
| Explanation |
On July 20, 1976 [ http://science.nasa.gov/headlines/y2001/ast20jul_1.htm ], NASA's Viking 1 lander became the first [ http://www.star.le.ac.uk/edu/solar/sovmars.html ] U.S. spacecraft to land on Mars [ http://cmex-www.arc.nasa.gov/ ], followed weeks later by its twin robot explorer, the Viking 2 lander. Operating [ http://photojournal.jpl.nasa.gov/cgi-bin/ PIAGenCatalogPage.pl?PIA00563 ] on the Martian surface [ http://nssdc.gsfc.nasa.gov/photo_gallery/ photogallery-mars.html#surface ] into the early 1980s, the Vikings took [ http://history.nasa.gov/SP-425/cover.htm ] thousands of pictures, conducted [ http://nssdc.gsfc.nasa.gov/planetary/viking.html ] sophisticated chemical searches for life [ http://history.nasa.gov/SP-4212/ch11-6.html ], and studied the martian weather [ http://www-k12.atmos.washington.edu/k12/resources/ mars_data-information/mars_overview.html ] and geology. In the dramatically detailed image above, a field of rocks and boulders is viewed from the Viking 1 landing site on Chryse Planitia (the Plain of Chryse). Viking 1's dusty foot pad is just visible at the lower right. The image was created [ http://nssdc.gsfc.nasa.gov/photo_gallery/caption/ vikinglander1-2.txt ] by combining high resolution black and white images with lower resolution color images of the same area. NASA is continuing its well chronicled [ http://history.nasa.gov/SP-4212/on-mars.html ] martian exploration program as the Mars Odyssey [ http://mars.jpl.nasa.gov/odyssey/ ] spacecraft is scheduled to arrive at the mysterious [ http://antwrp.gsfc.nasa.gov/apod/ap970528.html ] Red Planet on October 24th. What's Mars like today [ http://science.nasa.gov/headlines/y2001/ ast16jul_1.htm ]? |
|
A Piece of Interplanetary Du
…
| Title |
A Piece of Interplanetary Dust |
| Explanation |
The dust that pervades our Solar System is not the dust that pervades our homes. Solar System [ http://www.nineplanets.org/overview.html ] dust comes from comets [ http://antwrp.gsfc.nasa.gov/apod/comets.html ] and asteroids [ http://antwrp.gsfc.nasa.gov/apod/asteroids.html ], whereas house dust [ http://www.ag.ohio-state.edu/~ohioline/cd-fact/0191.html ] is most likely lint or dead cells. Pictured above [ http://stardust.jpl.nasa.gov/science/sd-particle.html ] is a piece of interplanetary dust [ http://www.astro.washington.edu/brownlee/ ] caught by a high-flying U2 [ http://142.26.194.131/aerodynamics1/Appendix/Aircraft/U2.html ]-type aircraft. It likely originates in the early days of our Solar System [ http://www.fourmilab.ch/solar/solar.html ], being stored and later ejected by a passing comet [ http://antwrp.gsfc.nasa.gov/apod/ap010527.html ]. The particle is composed of glass [ http://antwrp.gsfc.nasa.gov/apod/ap000322.html ], carbon [ http://pearl1.lanl.gov/periodic/elements/6.html ], and a conglomeration of silicate mineral grains [ http://antwrp.gsfc.nasa.gov/apod/ap010523.html ]. It measures only 10 microns [ http://www.physlink.com/reference_conversion.cfm ] across, a tenth the width of a typical human hair [ http://library.thinkquest.org/26829/text-only_3-hairy_e.htm ]. NASA's STARDUST [ http://stardust.jpl.nasa.gov/cool.html ] mission, launched [ http://antwrp.gsfc.nasa.gov/apod/ap990405.html ] in 1999, is scheduled to pass through the tail of Comet Wild 2 in 2004 and return [ http://antwrp.gsfc.nasa.gov/apod/ap990218.html ] many more interstellar dust [ http://antwrp.gsfc.nasa.gov/apod/ap981121.html ] samples to Earth [ http://antwrp.gsfc.nasa.gov/apod/ap010204.html ] in 2006. |
|
Deimos: A Small Martian Moon
| Title |
Deimos: A Small Martian Moon |
| Explanation |
Mars has two tiny moons, Phobos [ http://antwrp.gsfc.nasa.gov/apod/ap010818.html ] and Deimos [ http://www.nineplanets.org/deimos.html ]. Pictured above [ http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/vo2_428b60.html ] is Deimos [ http://www.exploringmars.com/science/deimos.html ], the smaller moon of Mars. In fact, Deimos [ http://antwrp.gsfc.nasa.gov/apod/ap010902.html http://www.solarviews.com/eng/deimos.htm ] is one of the smallest known moons in the Solar System [ http://www.exploratorium.edu/ronh/solar_system/ ] measuring only nine miles across. The diminutive Martian moons were discovered in 1877 by Asaph Hall [ http://www.usno.navy.mil/hallmedal.html ], an American astronomer [ http://www.aas.org/ ] working at the US Naval Observatory [ http://www.usno.navy.mil/ ] in Washington D.C. [ http://www.washingtondc.gov/ ] The existence of two Martian moons was predicted around 1610 by Johannes Kepler [ http://antwrp.gsfc.nasa.gov/apod/ap010114.html ], the astronomer who derived the laws of planetary motion [ http://observe.ivv.nasa.gov/nasa/education/reference/orbits/orbit_sim.html ]. In this case, Kepler's prediction [ http://www.seds.org/billa/tnp/hypo.html#mars ] was not based on scientific principles, but his writings and ideas were so influential that the two Martian moons are discussed in works of fiction such as Jonathan Swift [ http://www.genealogy.org/~ajmorris/ireland/swift.htm ]'s Gulliver's Travels [ http://www.jaffebros.com/lee/gulliver/ ], written in 1726, over 150 years before their actual discovery [ http://www.ips.gov.au/papers/richard/moons_of_mars.html ]. |
|
Auroras Over Both Earth Pole
…
| Title |
Auroras Over Both Earth Poles |
| Explanation |
Auroras [ http://www.exploratorium.edu/learning_studio/auroras/ ] in the north and south can be nearly mirror images of each other. Such mirroring had been suspected for centuries but dramatically confirmed [ http://eiger.physics.uiowa.edu/%7Evis/conjugate_aurora/ ] only last month by detailed images from NASA [ http://www.nasa.gov/ ]'s orbiting Polar spacecraft [ http://www.geophys.washington.edu/Space/SpaceExp/POLAR/ ]. Pictured above [ http://www.gsfc.nasa.gov/topstory/20011025aurora.html ], a time-lapse movie shows simultaneous changes in aurora borealis [ http://www.imv.uit.no/english/science/publicat/waynorth/wn1/contents.htm ], at the top, and aurora australis [ http://ast.leeds.ac.uk/haverah/spaseman/aurora.shtml ], at the bottom. A cloud of electrons and ions moving out from the Sun on October 22 [ http://www.spaceweather.com/aurora/gallery_21oct01.html ] created [ http://www.spaceweather.com/glossary/imf.html ] the auroras [ http://www-istp.gsfc.nasa.gov/Education/whaur1.html ]. The solar explosion [ http://antwrp.gsfc.nasa.gov/apod/ap000309.html ] that released the particles [ http://www-istp.gsfc.nasa.gov/Education/waurora2.html ] occurred about three days earlier. |
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A Radar Image of Planet Eart
…
| Title |
A Radar Image of Planet Earth |
| Explanation |
This image of Mt. Rainier, Washington USA, planet Earth [ http://volcano.und.nodak.edu/vwdocs/volc_images/img_rainier.html ], was produced by the Spaceborne Radar Laboratory [ http://southport.jpl.nasa.gov/desc/SIRCdesc.html ] which flew on the Space Shuttle Endeavour [ http://antwrp.gsfc.nasa.gov/apod/ap950807.html ] in 1994. Radar, short for RAdio Detection And Ranging, is a technique which coordinates the operation of a radio transmitter and receiver to measure the direction, strength, and timing of radio echos from the surface of distant objects. An actual image of an object can be constructed by recording and analyzing many echos. One advantage of using radar imaging in planetary studies is that images can be made regardless of cloud cover or lighting conditions. During the early 90s, NASA's Magellan spacecraft [ http://nssdc.gsfc.nasa.gov/planetary/magellan.html ] was able to use radar imaging to produce similar high resolution maps of the surface of Venus [ http://antwrp.gsfc.nasa.gov/apod/ap950822.html ]. For more information about the picture click here [ http://southport.jpl.nasa.gov/pio/volcanos/captions/srl2-rainier_cap.html ]. Tomorrow's picture: A World Explorer |
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Deimos: A Small Martian Moon
| Title |
Deimos: A Small Martian Moon |
| Explanation |
Mars [ http://antwrp.gsfc.nasa.gov/apod/ap950721.html ] has two tiny moons, Phobos [ http://antwrp.gsfc.nasa.gov/apod/ap951002.html ] and Deimos. Pictured above is Deimos [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/deimos.html ], the smallest moon of Mars [ http://stardust.jpl.nasa.gov/planets/welcome/mars.htm ]. In fact, Deimos is the smallest known moon [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/ datamax.html#smallest ] in the Solar System measuring only 9 miles across. The diminutive Martian moons were discovered in 1877 by Asaph Hall [ http://www.usno.navy.mil/histnots.html ], an American astronomer working at the US Naval Observatory [ http://www.usno.navy.mil/ ] in Washington D.C. The existence of two Martian moons was predicted around 1610 by Johannes Kepler [ http://www.seds.org/billa/tnp/help.html#kepler ], the astronomer who derived the laws of planetary motion. In this case, Kepler's prediction [ http://www.seds.org/billa/tnp/hypo.html#mars ] was not based on scientific principles, but his writings and ideas were so influential that the two Martian moons are discussed in works of fiction such as Jonathan Swift's "Gulliver's Travels" [ gopher://gopher.vt.edu:10010/02/146/1 ], written in 1726, over 150 years before their actual discovery. |
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Summer at the South Pole
| Title |
Summer at the South Pole |
| Explanation |
December 22 marks the Winter [ http://www.astro.washington.edu/strobel/naked-eye/naked-eye.html#A1.2.4.5 ] Solstice - the beginning of winter in the Earth's northern hemisphere, and the first day of summer [ http://www.astro.washington.edu/strobel/naked-eye/naked-eye.html#A1.2.4.5 ] in the south! This view of Earth's southern hemisphere [ http://www.jpl.nasa.gov/galileo/slides/slide7.html ] near the beginning of its summer was created using images from the Galileo spacecraft taken during the December 1990 flyby [ http://www.jpl.nasa.gov/galileo/messenger/oldmess/Earth2.html ]. Dramatically centered on the South Pole [ http://www-news.uchicago.edu/South_Pole/South_Pole.html ], this mosaic was constructed by piecing together images made over a 24 hour period so that the surface appears to be entirely in sunlight. South America (middle left), Africa [ http://antwrp.gsfc.nasa.gov/apod/ap950622.html ] (upper right), and Australia (lower right), are visible as dark masses while Antarctica [ http://quest.arc.nasa.gov/livefrom/livefrom.html ] gleams brightly in the center. Swirling clouds marking the major weather systems are also prominent. |
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MyCn18: An Hourglass Nebula
| Title |
MyCn18: An Hourglass Nebula |
| Explanation |
The sands of time are running out for the central star of this hourglass-shaped planetary nebula [ http://fusedweb.pppl.gov/CPEP/ Chart_Pages/5.Plasmas/Nebula/Planetary.html ]. With its nuclear fuel [ http://fusedweb.pppl.gov/default.html ] exhausted, this brief, spectacular, closing phase of a Sun-like star's life [ http://www.astro.virginia.edu/class/hawley/astr124/starbirth.html ] occurs as its outer layers are ejected - its core becoming a cooling, fading white dwarf [ http://antwrp.gsfc.nasa.gov/apod/ap000910.html ]. In 1995, astronomers used the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap010806.html ] (HST) to make a series of images of planetary nebulae [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], including the one above [ http://www.stsci.edu/pubinfo/PR/96/07.html ]. Here, delicate rings of colorful glowing gas (nitrogen [ http://pearl1.lanl.gov/periodic/elements/7.html ]-red, hydrogen [ http://pearl1.lanl.gov/periodic/elements/1.html ]-green, and oxygen [ http://pearl1.lanl.gov/periodic/elements/8.html ]-blue) outline the tenuous walls of the "hourglass". The unprecedented sharpness of the HST images has revealed surprising details [ http://www.stsci.edu/pubinfo/gif/Hourgls.txt ] of the nebula ejection process [ http://antwrp.gsfc.nasa.gov/apod/ap960117.html ] and may help resolve the outstanding mystery of the variety of complex shapes and symmetries of planetary nebulae [ http://www.astro.washington.edu/balick/WFPC2/index.html ]. |
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The Ion Tail of Comet Hyakut
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| Title |
The Ion Tail of Comet Hyakutake |
| Explanation |
This picture of Comet Hyakutake [ http://www.eso.org/educnpubrelns/phot-23-96.html ] was taken on March 14, 1996. Structure in the ion tale of Comet Hyakutake [ http://www.astro.washington.edu/astro422/comets.html ] is now clearly visible. An ion tale forms as a comet nears the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap950813.html ]. Sunlight causes gas and dust to boil off the comet's solid nucleus. Charged gas - called ions - are then accelerated away from the Sun [ http://antwrp.gsfc.nasa.gov/apod/ap951004.html ] by the solar wind [ http://www-spof.gsfc.nasa.gov/Education/wsolwind.html ] - fast moving particles streaming out from the Sun's corona [ http://antwrp.gsfc.nasa.gov/apod/ap951024.html ]. The ion tale will appear blue and glows by fluorescence [ http://charlie.ab.umd.edu/jf/info.html ]. As Comet Hyakutake [ http://cfa-www.harvard.edu/cfa/ps/info1996B2.html ] gets closer to the Sun during the next month, a dust tail is expected to be visible as well. Dust [ http://antwrp.gsfc.nasa.gov/apod/ap960125.html ] tails shine by light reflected from the Sun. Comet tails [ http://antwrp.gsfc.nasa.gov/apod/ap950826.html ] point away from the Sun, even as a comet moves away from the Sun. For observers in the Northern Hemisphere, Comet Hyakutake should appear tonight [ http://encke.jpl.nasa.gov/C1996B2/C1996B2_guide.html ] in the eastern part of the constellation of Virgo and should be about magnitude 2.5. The comet will look the most impressive in the darkest skies - in a city you are likely to see only a fuzzy blob! |
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Comet Hyakutake's Past and F
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| Title |
Comet Hyakutake's Past and Future |
| Explanation |
The above false-color picture of Comet Hyakutake taken just two days ago shows its rapidly developing tail. The comet now has a substantial coma [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#coma ] with a bright center, lending it a dramatic eye-like appearance [ http://antwrp.gsfc.nasa.gov/apod/lib/gliba960322.html ]. This is "not" Comet Hyakutake [ http://cfa-www.harvard.edu/cfa/ps/info1996B2.html ]'s first visit to the inner Solar System. Recent orbital determinations [ http://newproducts.jpl.nasa.gov/comet/hyakutake/ephemjpl2.html ] clearly show Comet Hyakutake [ http://newproducts.jpl.nasa.gov/comet/hyakutake/index.html ]'s was here before, although the previous approach is estimated to be about 8600 years ago - during the epoch of the first recorded human cities. Were this the comet's first trip to the inner Solar System [ http://antwrp.gsfc.nasa.gov/apod/ap950819.html ], it probably would not appear as bright as it does now - first time comets typically do not shed as much luminous gas as veterans. Before making any approach to the inner Solar System, Comet Hyakutake [ http://www.astro.washington.edu/astro422/comets.html ] was dormant in the Oort cloud [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/kboc.html ] of the outer Solar System for a few billion years, along with hundreds of thousands of similar comets. Comet Hyakutake is predicted to become the brightest comet since Comet West [ http://antwrp.gsfc.nasa.gov/apod/ap950826.html ] in 1976, which rivaled the brightest stars in the sky. Tonight [ http://encke.jpl.nasa.gov/C1996B2/C1996B2_guide.html ], Comet Hyakutake can be seen best from about 10 pm [ http://www.skypub.com/comets/hyaku3.html#top ] near the Big Dipper's handle. [ http://antwrp.gsfc.nasa.gov/apod/ap960322.html ] |
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Where to See Comet Hyakutake
| Title |
Where to See Comet Hyakutake |
| Explanation |
People the world over are preparing to witness the closest approach of the brightest comet of the past twenty years. Comet Hyakutake [ http://www.jpl.nasa.gov/comet/hyakutake/ ], discovered just two months ago, will pass nearest the Earth Monday morning. All during the coming week, Comet Hyakutake [ http://antwrp.gsfc.nasa.gov/apod/ap960319.html ] will be visible in the northern sky [ http://www.skypub.com/comets/hyaku3.html#top ] as an unusual extended fuzzy patch. To see the comet is not difficult - just go outside and look up [ http://antwrp.gsfc.nasa.gov/apod/lib/gliba960322.html ] - no telescope is required! The comet's location in the sky during late March is charted above. The horizon is drawn for about 8 pm in your local time. By about 11 pm, Comet Hyakutake [ http://cfa-www.harvard.edu/cfa/ps/info1996B2.html ] will be high in the sky and well placed for viewing. Although Comet Hyakutake [ http://www.astro.washington.edu/astro422/comets.html ] is whizzing past the Earth at a blistering speed of almost 100,000 miles per hour, and it is practically streaking across the sky by astronomical standards, it will appear to move only a few degrees on any given night. Each night this weekend and in the coming week, the comet will be visible. Please don't miss this rare and exciting astronomical event! |
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Europa: Oceans of Life?
| Title |
Europa: Oceans of Life? |
| Explanation |
Is there life beneath Europa's frozen surface? Some believe the oceans found there of carbon-enriched water are the best chance for life [ http://www.etext.org/Zines/Quanta/life.html ], outside the Earth [ http://ucmp1.berkeley.edu/alllife/threedomains.html ], in our Solar System [ http://antwrp.gsfc.nasa.gov/apod/ap950819.html ]. Europa [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/europa.html ], the fourth largest moon of Jupiter [ http://antwrp.gsfc.nasa.gov/apod/ap950714.html ], was recently discovered [ http://www.stsci.edu/pubinfo/press-releases/95-12.txt ] to have a thin oxygen atmosphere by scientists using the Hubble Space Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap950810.html ]. Although Earth's atmospheric [ http://www.aspire.cs.uah.edu/~jonesj/r.html ] abundance of oxygen is indicative of life [ http://www.gtri.gatech.edu/rh-win96/oxygen.htm ], astronomers speculate that Europa's oxygen arises purely from physical processes. But what an interesting coincidence! The above picture was taken by a Voyager spacecraft [ http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-voyager.html ] in 1979, but the spacecraft Galileo [ http://www.jpl.nasa.gov/galileo/index.html ] is currently circling Jupiter [ http://antwrp.gsfc.nasa.gov/apod/lib/jupiter.html ] and has been photographing [ http://www.jpl.nasa.gov/galileo/countdown/g1time.html ] Europa [ http://bang.lanl.gov/solarsys/europa.htm ]. The first of these pictures will be released two days from today. Will they show the unexpected? [ http://www.vsc.washington.edu/academic/499/Resources/europa.html ] |
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The Equal Night
| Title |
The Equal Night |
| Explanation |
Today the Sun crosses the celestial equator [ http://www.astro.washington.edu/strobel/naked-eye/ naked-eye.html#A1.2.4 ] heading south -- marking the Autumnal Equinox, the first day of Autumn. Equinox means "equal night" and with the Sun on the celestial equator [ http://www.physics.csbsju.edu/astro/CS/CSintro.html ], Earthlings will experience 12 hours of daylight and 12 hours of darkness. Then, for those in the northern hemisphere, the days will begin to grow shorter with the Sun marching [ http://www.lalc.k12.ca.us/laep/smart/Sunrise/k3les1.html ] lower in the sky as winter approaches [ http://www.astro.washington.edu/strobel/naked-eye/ naked-eye.html#A1.2.4.5 ]. A few weeks after the Autumnal Equinox of 1994, the Crew of the Shuttle Endeavor [ http://antwrp.gsfc.nasa.gov/apod/ap950807.html ] recorded this image [ http://images.jsc.nasa.gov/images/pao/STS68/20172510.htm ] of the Sun poised above the Earth's limb. The glare illuminates Endeavor's vertical tail (pointing toward the Earth) along with radar equipment [ http://southport.jpl.nasa.gov/ ] in the payload bay. |
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